High frequency stabilizer



Sept.,8, 1931. A; HYLAND HIGH FREQUENCY STABILIZER Filed March 26, 1929 2 Sheets-Sheet l IN V EN TOR. Wow) mzvzy a/w/ume/ a,

P 8, 1931- L. A. HYLAND 1,822,812

HIGH FREQUENCY STABILIZER Filed March 26, 1929 2 Sheets-Sheet 2 INVENTOR. ("MW 61 669K444),

fwwvwv ATTORNEY Patented Sept. 8, 1931 UNITED STATES PATENT OFFlC LAWRENCE A. HYLAND, OF WASHINGTON, DISTRICT F COLUMBIA, ASSIGNOR T0 WIRED RADIO, INQ, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE HIGH FREQUENCY STABILIZEl-t Application filed March 26, 1829. Serial No. 350,053;

My invention relates broadly to frequency stabilization generally and more particularly to the stabilization of high frequency signaling energy.

One of the objects of my invention is to provide a system for maintaining the fre-' quency of a high frequency generator substantially constant. I

Another object of my invention is to -provide a system for maintaining constant the frequency characteristics of a thermionic tube oscillatory circuit.

Still another object of my invention is to provide a frequency stabilizer whereby changes in the frequency characteristics of a circuit are readily and automatically controlled.

A further object of my invention is to provide means for automatically stabilizing the frequency of the generated energy from a high power oscillatory circuit.

A better understandin of my invention can be had from the speci cation hereinafter following and by reference to the accompanying drawings, wherein:

. Figures 1 and 2 are schematic circuit diagrams showing the frequency stabilizing system of my invention.

It is well known that generators of a low frequency energy and of high frequency energy may be easily constructed wherein the the frequency of the generated energy is substantially constant. There is a limit, however, to the amount of energ that can be generated by such constant fi'equency me-v thods as are employed, it being necessary to employ thermionic tube amplifying circuits of one or more stages to obtain the necessary power, in which frequency variations are likely to occur. It is more economical and desirable that sufficient power he initially generated to avoid the necessity ofemploying amplifier circuits. It is desirable that not more than a single amplifier tube be employed. The means commonly employed for generating constant frequency energy usually employ mechanically vibratile elements such 'asquartz crystals having piezo electric properties, magnetostriction rods and the like. In the frequency stabilization system of my invention such sources of constant fre quency energy are employed to directly control the frequency of the generated energy without the necessity of employing a multi- Elicity of high power themionic tube ampliers.

Fig. 1 of the drawings is a schematic circuit diagram showing the constant frequency control embodying my invention. Thermionic tube 1 is shown as of thetriode type having a cathode, control electrode and anode,

but may be of anysuitable design such as the shielding anode type of tube. Thermionic tube 1 has an input circuit 2 and output circuit 3. Adjustable condenser 4 is employed, schematically, representing means for adjusting the fre uency characteristics of circuits 2 and 3. tlircuits 2 and 3 of thermionic tube 1 comprise the oscillatory circuit whereby the high frequency signaling energy is generated. The high frequency oscillatory circuit of thermionic tube 1 is connected with the input circuit of thermionic tube 5. The output circuit of thermionic tube 5 comprises inductance 6, which inductance is connected with space radio radiating system or load circuit 7. Thermionic tube 5 and its input and output circuits comprise a high frequency am lilier. Thermionic tube 8 is of suitable design and has an input and an output circuit. The input circuit of thermionic tube 8 includes source of biasing potential 15'for the control electrode, choke coil 16 and blocking condenser 17, the latter being connected in series with inductances 9 and 14. Inductances 9and 14 may be adj ustable thereby permitting .variation of the frequency characteristics, adjustable couplin or both frequency variation and couplingla justmentl The out-- put circuit of thermionic tube 8 includes induetances 18 and 19 positioned substantially as illustrated. Inductances 20 and 21 are placed at substantially 90 with respect to each other and in close proximity to inductances 18 and 19.

Inductances 20 and 21 are connected in series, a common connection joining one end of both inductances 20' and 21, the remaining ends connected together through inductance 22 and resistance 28, respectively. A

. high frequency oscillator of constant frequency energy comprises thermionic tube 10 having a mechanically vibratile element 11 comprising its input circuit and an output circuit including inductance 12 and capacity 13. Inductance 12 is inductively coupled with inductance 14 of thermionic tube 8. Thermionic tube 26 comprises a low frequency oscillator. The input circuit of thermionic tube 26 includes a mechanically vibratile element 27, contact member 31 and source 32. Electromagnet 28 is connected in series with contact member 30, source 29 and element 27. Vibrations of element 27 are sustained by electromagnet 28 whereby contact members 31 are opened and closed in accordance with the fundamental period orfrequency characteristics of element 27. This causes variations of impressed potential to be supplied the control electrode of thermionic tube 26. The output circuit of thermionic tube 26 includes inductance 25 which is connected with inductances 20, 21 through inductance 22 and resistance 23, respectively. Inductance 22 and resistance 23 cause a phase displacement of the energy from thermionic tube 26.

The operation of the arrangement shown in Fig. l as tohigh frequency oscillator 1 and amplifier 5 is similar to that generally familiar to those skilled in the art. High frequency energy from amplifier 5 and high frequency energy from constant frequency oscillator 10 is transferred in part to inductances 9 and 14 connected with thermionic tube 8.

Thermionic tube 8 has the proper biasing potential impressed upon its control elec trode whereby the operating characteristics of the tube are substantially those of a rectifier. Thermionic tube 8, acting as a rectifier, causes a beat frequency to be produced in its output circuit the frequency of which is either the sum of the frequencies of the energy from amplifier 5 and oscillator 10 or the difierence of these frequencies. To avoid confusion the difference frequency alone will be referred to, this frequency being that of a low order and the sum frequency that of a higher order. Inductances 9 and 14 may be adjusted whereby the ratio of the energy from amplifier 5 to that of the energ from generator 10 may be controlled at will. In-

d'uctances 20 and 21 are energized from source of low frequency energy 26. Inductance 22 and resistance 23 serve to split the phase of the current applied to inductances 20 and 21 thereby establishing a rotating magnetic field. Inductances 20 and 21 are physical coils mounted on a pivot and in mechanical relation with adjustable condenser 4 as indicated by the dotted line 4a, as by being mounted on a common shaft. WVhen the frequency of the energy in inductances 18, 19 is the same as the frequency of the energy in inductances 20, 21 no motion is transmitted to adjustable condenser 4. \Vhen, however, the frequency of the energy in inductances 18, 19 differs from the frequency of the energy in inductances 2t), 21 the latter are moved in a given direction transmitting the motion to adjustable condenser 4. The direction of such movement in turn depends u on whether the beat frequency is greater than or less than the frequency of the energy from low frequency generator 26.

The are through which the movement occurs is proportional to such difference of frequency. It is obvious that the movement of inductance members 21), 21, corresponding to a given frequency change, can be caused to change the frequency chararteristics of circuit 2, 3 by condenser 4, suflicient-ly to correct for such frequency change. An increase in the frequency of the energy from amplifier 5 may cause the movement of inductance members 20, 21 and a corresponding change in the adjustment of condenser 4, thereby decreasing the frequency characteristics of circuits 2, 3 of thermionic tube 1. Since this is the source where the energy was originally produced of a frequency determined by the circuit 2, 3 and 4, correction of the frequency characteristics of this circuit corrects the fre quency change. It can readily be seen that when the change in frequency has been corrected the rotating field is no longer produced, inductance members 20, 21 and adjustable condenser 4 remaining stationary. An increase of frequency or a decrease of frequency again causes the movementof inductance members 20, 21 effecting a change in the adjustment of condenser 4 thereby correcting the change of frequency.

Fig. 2 of the drawings shows a modification of the frequency stabilizing means of m invention. Inductance members 18, 19, 20 and 21 are herein shown diagrammatically. Reference characters correspond to those shown in Fig. 1. Condenser plates 35 and 36 constitute a variable condenser which is electrically connected in parallel with condenser 4. Inductance 9 of the input circuit of thermionic tube 8 is coupled with the oscillatory circuit of thermionic tube 1. I

Grid leak and condenser 17a serveto control the operating characteristics of thermionic tube 8 whereby the same functions as a rectifier. By means of connector 14a connected with inductance 12, a portion of the output circuit of thermionic tube serves as a portion of the input circuit of thermionic tube 8. Thermionic tube 26 has inductance members and 21 comprising in part the output circuit. A potential of negative polarity is normally impressed upon the control electrode of thermionic tube 26 by source 32 through resistor 34. Connecting member 33 is connected with resistor 34 in such manner that when contact members 31 are closed a value of potential other than normal is impressed upon the control elec trode of tube 26. Contact members 31 are actuated by electromagnet 28 at the frequency of member 27 Condenser plate members 35 and 36 are of suiiicient area to compensate for minute changes as might ordinarily be experienced. Condenser plate member 35 may be of suitable metal of light weight such as aluminum or aluminum foil positioned on either inductance member 20 or 21. One of plates 20 or 21 may be adjustable whereby the desired capacity value may be determined for the frequency desired. Connections from resistor 23, inductance 22 and series connection 24 may be established net-tors as desired.

by movable commutator rings or flexible con- Inductance members 20 and 21 may be of any suitable design suitably pivoted whereby the friction is reduced. Inductance 9, comprising in part the input circuit of thermionic tube 8, is coupled with the oscillatory circuit of thermionic-tube 1. Amplifier 5 may or may not be employed depending upon the power rating of thermionic tube 1 and the energy desired in load circuit 7.

Many modifications of my invention are possible without departing from the spirit of my invention where movable coils are adjacent to stationary coils and whereby change in the frequency in one of the circuits causes a correction of the frequency causing such change. The movable coils may be connected with any frequency adjusting device such as a variometer or adjustable inductance. The movable coils may be excited by the beat frequency heretofore referred to and the stationary coils excited by the source of constant frequency energy. Inductance coils 18 and 19 may be movable and inductance coils 20 and 21 stationary. The frequency characteristics of the input circuit and of the output circuit may be separately controlled or con trolled in common as shown in the drawings. Inductance coils 18, 19, 20 and 21 may be constructed in any suitable manner, the mov-.

able coils pivoted or supported in any convenient way. Low frequency oscillator 26 may be of any suitable design and connected with or independent of an amplifier circuit.- The high frequency energy from thermionic tube 1 may be coupled to rectifier tube 8- by capacity, inductance or in any suitable manner. The energy from either source 1 or source 10 may be coupled to the output circuit of rectifier 8 instead of both sources 1 and 10 being coupled to the input circuit as shown. The frequency employed as a beat frequency may be of any suitable value including those of super-sonic "aluc. The frequency from generator 26 should be of approximately the same value. The energy of the beat frequency may be caused to be equal in amplitude to the energy from generator 26 by means of the several adjustments provided. The output of thermionic tube 1 may be connected directly with the radiating system, the power of thermionic tube 1 being any value desired.

It is to be understood that the embodiments .of my invention are not to be restricted by the foregoing specification or by the accompanying drawings but only by the limitations Imposed by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Means for maintaining constant the frequency characteristics of a high frequency circuit, comprising in combination a primary source of high frequency energy in said circuit, an independent standard source of constant frequency energy, a rectifier having an input circuit connected with both of said sources of energy whereby a beat frequency is produced in the output circuit ofsaidrectifier, stationary inductance coils in fixed mutual relative position, connected with said output circuit energized by said beat frequency, movable coils in inductive relation to said stationary coils and energized by an independent source of energy having a low frequency approximately the same as said beat frequency, and frequency adjusting means of said first mentioned circuit mechanically connected with said movable inductance coils.

2. Means for maintaining the frequency characteristics of a high frequency circuit constant comprising in combination a primary source of high frequency energy in said circuit, an independent standard source of constant frequency energy, a rectifier having an'input circuit coupled with both of said sources of high frequency energy whereby a beat frequency is produced in the output cir- 11 cuit of said rectifier, said beat frequency in said output circuit connected with a stationary inductance coil, a source of constant fre: quency energy of a low frequency value approximately equal to said beat frequency connected with a movable inductance coil in inductive relation to said stationary inductance, and said movable inductance mechanically connected with frequency adjusting means of said first mentioned circuit.

3. Means for maintaining the frequency characteristics of a high frequency circuit constant comprising in combination a primary source of high frequency energy in saidcircuit, an independent standard source of 1 mary source of high output circuit of said rectifier, stationary inductance coils connected with said output circuit energized by said beat frequency, movable coils in inductive relation to said stationary coils, an independent source of energy having a low frequency approximately the same as said beat frequency connected for energizing said movable coils, and frequency adjusting means of said first mentioned circuit mechanically connected with said movable inductance coils.

4. Means for maintaining the frequency characteristics of ahigh frequency circuit constant comprising in combination a prifrequency energy in said circuit, an independent'standard source of constant frequency energy, a rectifier having an input circuit coupled with both of said sources of high frequency energy whereby a beat frequency is produced in the output circuit of said rectifier, said beat frequency in said output circuit connected with a stationary inductance coil, a source of constant fre-' quency energy of a frequency approximately the same as said beat frequency connected with a movable inductance coil in inductive relation to said stationary inductance and said movable inductance mechanically connected with frequency adjusting means of said first mentioned circuit.

5. In a high frequency stabilizing system the combination of a movable inductance coil a source of constant frequency energy connected for exciting said movable inductance coil, a stationary inductance coil positioned adjacent to said movable inductance coil, a generating circuit carrying oscillations the frequency characteristics of which are to be stabilized, with an independent source of constant low frequency energy, a rectifier coupled with said generating circuit and said independent source of low frequency energy, the beat frequency produced in the output circuit of said rectifier'beingconnected with said stationary coil and said movable coil being mechanically connected with frequency adjusting means of said circuit the frequency characteristics of which are to be stabilized.

6. In a. system for stabilizing the frequency characteristics of a high frequency circuit the combination of a rectifier, a constant' frequency of said rectifier being coupled with the energy from said high frequency circuit and with said constant frequency generator, the output circuit of said rectifier. connected with a stationary inductance coil, a movable inductance coil inductively related to said stationary inductance coil, a second source of constant low frequency energy connected for generator, the input circuit frequency adjusting means of said first mentioned circuit.

7. Means for maintaining the frequency characteristics of a high frequency circuit,

constant, comprising in combination a primary source of high frequency energy in said circuit, an independent standard source of constant frequency energy, a rectifier having an input circuit coupled with both of said source *1 of energy whereby a beat frequency is produced in the output circuit of said rectifier, stationary inductance coils connected with said out put circuit energized by said beat frequency; movable coils in inductive relation to said stationary coils energized by an independent source of energy having a low frequency approximately the same as said beat frequency, phase displacing circuits connected with said coils, and

frequency adjusting means of said first mentioned circuit mechanconstant, comprising in combination a primary source of high frequency energy in said circuit, an independent source of constant high frequency energy, a rectifier having an input circuit coupled with both of said sources of high frequencyenergy whereby a beat frequency is produced in the output circuit of said rectifier, said beat frequency in said output circuit connected with a stationary inductance coil, a source of constant frequency energy of a low frequency value approximately the same as said beat frequency connected with a movable. inductance coil in inductive relation to said stationary inductance, phase displacing circuits connected with said coils, and said movable inductance mechanically connected with frequency adj usting means of said first mentioned circuit.

9. In asystem for stabilizing. the frequency characteristics of a high frequency circuit the combination of a rectifier, a constant frequency generator, the input circuit of said rectifier being coupled' with said high frequency circuit and said constant frequency generator, a source of constant low frequency energy, two inductance coil systems in mutual inductive relation and mounted for mutual relative motion, one of said inductance coil systems being connected with the output circuit of said rectifier, the other of said inductance coil systems being connected to said source of constant low frequency energy, and one of said inductance coil systems being mechanically connected with frequency adjusting means of said first mentioned circuit.

10. Means for maintaining the frequency characteristics of a high frequency circuit constant, comprising in combination a pritual inductive relation and mounted for mutual relative motion, one of said inductance coil systems being connected With the output circuit of said rectifier, the other of said inductance coil systems being connected to said source of constant low frequency energy, phase displacing circuits connected with said coils, and frequency adusting means of said first mentioned circuit mechanically connected with one of said inductance coil systems.

11. Means for maintaining the frequency characteristics of a high frequency circuit constant, comprising in combination a primary source of high frequency energy in said circuit, an independent standard source of constant frequency energy, a rectifier having an input circuitcoupled with both of said sources of high frequency energy whereby abeat frequency is produced in the outputcircuit of said rectifier, said heat frequencyin said output circuit connected with a stationary inductance coil, a source of constant low frequency energy connected, with a movable inductance coil in inductive relation to said stationary inductance, phase displacing circuits connected with said coils, and said movable inductance mechanically connected with frequency adjusting means of said first mentioned circuit.

12. In a high frequency stabilizing system, a primary source of high frequency current, a. standard source of high frequency current of constant frequency, a source of audio frequency currents of constant frequency, an

electron tube having its input circuit coupled to both said primary source and said standard source, a pair of inductance coil units in mutual inductive relation and mounted for mutual relative motion, one of said inductance coil units being connected to the output circuit of said electron tube, the otherof said inductance coil units being connected to said audio frequency source, and a circuit element of said primary source controlled by the position of one of said inductance coil units for controlling the frequency of said primary source.

13. In a high frequency stabilizing sys tem, a primary source of high frequency current, a standard source of high frequency current of constant frequency, a source of audio frequency currents of constant frequency, an electron tube having its input circuit coupled to both said primary source and said standard source, a pair of inductance coil units in mutual inductive relation and mounted for mutual relative motion, one of said inductance coil units being connected to the output circuit of said electron tube, the

other of said inductance 'coil units being con-. nccted to said audio frequency-source, phase displacing circuit elements connected between said audio frequency source and said inductauce coil unit, and a circuit. element of said primary source controlled by the position of one of said inductance coil units for controlling the frequency of said primary source.

LAWRENCE A. HYLAND. 

